Control of position sensor input to Ecdis on high speed craft

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DEPARTMENT OF CIVIL ENGINEERING NOTTINGHAM GEOSPATIAL INSTITUTE

CONTROL OF POSITION SENSOR INPUT TO ECDIS ON HIGH SPEED CRAFT

AUTHOR ODD SVEINUNG HAREIDE SUPERVISORS PROF ANDY NORRIS

DR CHRIS HILL DATE 4 OCTOBER 2013

Project thesis submitted in part fulfilment of the requirements for the degree of Master of Science in Position and Navigation Technology at The University of

Nottingham.

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Abstract

By 2018 all larger ships are to be equipped with Electronic Chart Display and

Information System (ECDIS). The paradigm shift from paper charts to electronic charts has been a technological leap for mariners, and the Integrated Navigation Systems (INS) are getting more and more complex. This leads to new challenges for the navigators of today.

Global Navigation Satellite Systems (GNSS) such as GPS are the primary position sensor input for ECDIS, and it has since its early beginning in the middle of the 1990s been very reliable. National and worldwide statistics show that there has been a slight increase in navigational accidents since the introduction of ECDIS, but the reasons for this is not clear. In the literature review it is laid down that position sensors have its potential fault, and GNSS and its augmentation systems is described to better understand its advantageous and limitations. Control of ECDIS with position control methods are explored, and divided into two methods of control: Visual- and

Conventional methods.

Through field work, simulator tests and interviews the findings are clear. The

navigators of today rely too much upon their primary position sensor which normally is a GNSS such as GPS. A questionnaire reveals that the navigators have insufficient deeper system knowledge of the navigation aids in use. This can lead to a potentially serious accident with loss of lives and large environmental damage. To achieve safe navigation it is important to continuously conduct control of primary position sensor input to ECDIS with a secondary position sensor by visual- and/or conventional control methods. The advantages and limitations with the different methods of control are discussed. Position sensors such as GNSS can fail, and navigators of today and

tomorrow need to monitor the position sensor input to ECDIS with other means than GNSS.

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Acknowledgement

First of all I would like to express my gratitude for all the positivity that has met me while working with this research project. It has become clear that the development of the craftsmanship of navigation, and especially within the field of ECDIS, is something that many think of and want to have a say in. Thanks to many colleagues for

enthusiastic and constructive discussion on this matter (none mentioned, none forgotten).

An extensive field work has taken place, and it would not be possible without the warm welcome and the open mind of people at the Norwegian Corvette Service and the Navigation Centre at the Royal Norwegian Navy. A special thanks to the simulator department at the Navigation Centre, for setting up and facilitating the simulator tests.

The staff and crew of ship owner NorLeds catamarans have also given me a warm welcome on board during the data collection.

During supplementary work with the research project, I have had meetings with scholars at Vestfold University College and Aalesund University College department of nautical engineering. This has been valuable and much appreciated feedback to the project.

Prof Andy Norris has provided guidance and interesting thoughts on the challenges I have encountered while writing this thesis. Dr Chris Hill has been supervising the project from the University of Nottingham, and I thank them for their feedback.

Finally I would like to express gratitude to my beloved family, Tone and Lilly, for their patience and support during this work.

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Abbreviations

6NK – Sixth semester Navigation Course AIS – Automatic Identification System ARP – Arm Rest Panel

AUC – Aalesund University College

CATZOC – Category of Zones of Confidence CO – Commanding Officer

DGPS – Differential Global Positioning System DNV – Det Norske Veritas

EBL – Electronic Bearing Line

ECDIS – Electronic Chart Display and Information System ECS – Electronic Chart System

EGNOS – European Geostationary Navigation Overlay System eLORAN – Enhanced Long Range Navigation

ENC – Electronic Navigation Chart ETA – Estimated Time of Arrival FD – Fault Detection

FDE – Fault Detection and Extraction FPB – Fast Patrol Boat

GBAS – Ground Based Augmentation System GNSS - Global Navigation Satellite System GPS – Global Positioning System

HMI – Human Machine Interface

HNoMS – His Norwegian Majesty`s Ship HSC – High Speed Craft

IBS – Integrated Bridgde System

IHO – International Hydrographic Organization IMO – International Maritime Organization INS – Integrated Navigation System

INaS – Inertial Navigation Sensor

ITU – International Telecommunication Union KTS – Knots (1knot = 1nm/hour)

LORAN – Long Range Navigation

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7 MFA – Ministry of Foreign Affairs

MFD – Multi Function Display MoD – Ministry of Defence

MTBT – Norwegian Corvette Service Training Centre MTBV – Norwegian Corvette Service

NNC - The Royal Norwegian Navy Navigation Centre NM – Nautical Mile (1nm = 1852metres)

OBD – Optical Bearing Device

ODGPS – Ordinary Differential Global Positioning Service OOW – Officer Of the Watch

PI – Parallel Index

PPS – Precise Positioning Service RADAR – RAdio Detection And Ranging

RAIM – Receiver Autonomous Integrity Monitoring RIB – Rigid Inflatable Boat

RNC – Raster Navigation Chart RNoN – Royal Norwegian Navy

RNoNA – Royal Norwegian Naval Academy SBAS – Space Based Augmentation System SENC – System Electronic Navigation Chart SNK – Skjold Navigation Course

SOA – Speed Of Approach SOLAS – Safety Of Life At Sea SPS – Standard Positioning Service SVK – Skjold Officer of the Watch Course UTC – Coordinated Universal Time VRM – Variable Range Marker VUC – Vestfold University College UoN – University of Nottingham

WAAS – Wide Area Augmentation System

WADGPS – Wide Area Differential Global Positioning System XTE – Cross Track Error

ZOC – Zones of Confidence

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Figures and Tables

Figure 2.1 ECDIS implementation ... 17

Figure 2.2 Ship accidents 2000-2010 ... 21

Figure 2.3 Serious accidents statistics... 23

Figure 2.4 Distribution of navigational versus non-navigational accidents ... 24

Figure 2.5 Comparison of factors in serious incidents HSC and Commercial vessels. .... 25

Figure 2.6 ECDIS interface ... 27

Figure 2.7 IBS of a military ship ... 28

Table 2.1 Category of Zones of Confidence Definitions ... 29

Figure 2.8 Domains of ECDIS competence ... 30

Figure 2.9 Dilution of Precision ... 32

Table 2.2 GPS error and biases ... 33

Figure 2.10 Multipath... 33

Figure 2.11 Comparison WADGPS and DGPS ... 35

Table 2.2 DGPS bias and errors ... 36

Figure 2.12 Chart contour overlay on RADAR ... 39

Figure 2.13 Comparison of RADAR track and AIS track. ... 42

Figure 2.14 Performance-Shaping Factors in navigation accidents ... 44

Figure 2.15 Education for navigator at Skjold-Class FPB ... 47

Figure 3.1 Sailing route simulator test ... 53

Figure 4.1 Area Lofoten ... 59

Figure 4.2 Patrol southwards ... 60

Table 4.1 Methods of control HNoMS Gnist ... 61

Figure 4.4 Use of notation in passage planning ... 62

Figure 4.5 Chart from Aalesund to Hareid ... 65

Figure 4.6 Chart from Bergen to Leirvik ... 66

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Table 4.2 Methods of control NorLed HSC ... 67

Figure 4.6 Time to detection of error in GPS position sensor input. ... 71

Figure 4.7 Amount of deviation when error detected ... 71

Table 4.3 Means of detecting error in position input ... 72

Figure 4.8 Drift in the system shown on RADAR console with the use of chart contour overlay ... 73

Figure 4.9 Comparing tracks to evaluate position sensor input. ... 74

Figure 4.11 Methods of control ... 76

Figure 4.12 Methods of control of position sensor input to ECDIS ... 77

Figure 4.13 Navigator system knowledge ... 78

Figure 4.14 Deeper system knowledge amongst navigators ... 79

Table 4.5 Pros and Cons with different control methods of ECDIS ... 87

Figure 6.1 Control of ECDIS ... 109

Figure 6.2 Means of control ... 110

Table 6.1 Methods of control... 111

Figure 6.3 Methods of control ... 111

Figure 6.4 Most efficient visual control ... 111

Figure 6.5 Position deviation alarm ... 112

Figure 6.6 Can GPS fail ... 112

Table 6.2 Questionnaire ... 119

Figure 6.7 User questions average score ... 120

Figure 6.8 Deeper technical level average score ... 121

Figure 6.9 EXCEL sheet ... 121

Figure 6.10 Design of simulator department at RNoNA. ... 122

Table 6.3 Notation used in the Norwegian Navy ... 123

Figure 6.11 Powerpoint presentation ... 130

Figure 6.12 4- bearing principle ... 131

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10 Figure 6.13 4- bearing principle in map ... 132 Figure 6.14 ½ bearing principle ... 133 Figure 6.15 EXCEL sheet simulator test statistics ... 134

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1.0 Introduction

1.1 Background

By the year 2018 all larger ships are to be equipped with Electronic Chart and Display Information System (ECDIS) (IMO, 2009). This has led to a paradigm shift from paper charts towards Electronic Charts and Integrated Navigation and Bridge Systems (INS/IBS). With this paradigm shift there will be navigators of today and navigators of tomorrow, with different knowledge and different perspective of what is important in their daily work as an Officer Of the Watch (OOW) on board a vessel.

The author has his background from The Royal Norwegian Corvette Service (MTBV), from both the Hauk-Class¹ and the Skjold-Class² Fast Patrol Boats (FPB). Even though the two classes of ships are products of different times, there are many similarities in their operational pattern. Both are high speed craft (HSC), operating primarily along the Norwegian coast. The Norwegian coast is known for its harsh and challenging environment, both with regards to weather but also due to a large number of islands and skerries. With 6 years of experience as a navigator on board Norwegian FPBs the author has experience from both paper charts and ECDIS.

When converting from paper charts to ECDIS, a new world within the field of

navigation had to be explored. This is still a path which is not well defined, and there are still findings and developments that refine the world of ECDIS. This will also be the case in the years to come. There has been a large leap in the right direction since the first passages with an ECDIS in the middle of the 1990s until the way it is done today.

Nevertheless, the refinement of ECDIS is not done yet.

The Royal Norwegian Naval Academy Navigation Centre (NNC) is a centre of excellence within navigation in the Royal Norwegian Navy (RNoN). The author has his work at NNC with navigation systems and education of cadets in navigation and in the use of ECDIS.

The navigators fresh out of school today are accused of being a product of the

“computer generation”, whose main problem is using more time looking at the

1 For further information about the Hauk-Class: http://en.wikipedia.org/wiki/Hauk-class_patrol_boat

2 For further information about the Skjold-Class: http://www.naval-technology.com/projects/skjold/

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12 computer screen than looking out the window of the bridge (Norris, 2010). Control of position sensor input to ECDIS is a term which has appeared (NNC, 2012, MTBTS, 2009, Norris, 2013a), and navigation teams are trained in this control method. The different ways of continuously controlling the position sensor input to the ECDIS provide the navigators with a toolbox for safe navigation, and also keep the navigators` eyes up and facing forward in the direction the craft is sailing. This method addresses both problems of (1) controlling the ECDIS and (2) keeping the navigators` attention out through the windows of the bridge and away from the screens on the bridge. All of the systems in an INS is crucial to monitor, but all these screens also lead to information overload and excessive workload for the navigator (Norris, 2010). Correct use of the systems and a good look-out are of high importance to enhance safe navigation.

ECDIS first arrived in the middle of the 1990s, and the move from paper chart to electronic chart has been a big move within the field of marine navigation. Both the author and many in the nautical community have had a feeling that there has become a knowledge gap when introducing this new technology to the marine world. The author has experience from HSC using both paper and electronic charts, and has been a part of this paradigm shift from paper to electronic charts. Through observations there has been identified a knowledge gap when moving from paper charts to the use of electronic charts and ECDIS-systems. This has evolved to writing this research thesis where further observations on board military and civilian HSC and tests in a controlled environment have taken place. Findings from this project aim to help future navigators to efficient and safe use of ECDIS when it comes to controlling the position sensor input. The research will also provide navigators with a toolbox of different control methods which will ease their work as an OOW in their daily work.

1.2 Research Focus

The focus of the research will be within the control methods of position sensor input chosen to ECDIS. Control methods are divided into visual and conventional control of ECDIS, which will be explained later on in the thesis. The platform of research will be high speed craft in littoral waters.

The reason for this focus is the fact that the position sensor input to ECDIS is primarily Global Navigation Service Systems (GNSS) such as Global Positioning System (GPS). This

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13 is a system with high reliability (Hofmann-Wellenhof, 2008), but it is possible that such a system can fail (Elliott D. Kaplan, 2006, Engineering, 2011). There are also areas of the world where the coverage of such systems are poor. Especially in the High North, which Norway is a part of, there are problems towards the reliability and coverage of GNSS with and without augmentation systems such as EGNOS and WAAS (Kjerstad, 2009). It is therefore fundamental that ECDIS is continuously monitored so that if a situation occurs where GNSS is degraded, this is known by the navigators and the passage can continue with other available means.

The research will be divided into two main parts:

1. Literature review

2. Field study. The field work will be divided into three subsections:

I. Field study on board military and civilian HSC.

a) Conduct observations of which control methods are used in controlling position sensor input to ECDIS.

II. Simulator test.

a) To explore and measure if navigators are controlling the position sensor input to the ECDIS, and to disclose how much time is needed for the OOW to detect position errors from the GNSS.

III. Interviews with navigators.

a) Part 1: Used as a brainstorming to examine what navigators find efficient when it comes to control of position sensor input to ECDIS, and two short questions with regards to system knowledge in relation to ECDIS.

b) Part 2: Questionnaire to examine system knowledge amongst navigators (in collaboration with fellow student Steinar Nyhamn (2013)).

1.3 Research Aim and Individual Research Objectives

1.3.1 Research Aim

How to improve and develop the control of position sensor input chosen to ECDIS on a High Speed Craft in littoral waters.

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14 1.3.2 Research Objective

The overall aim of this research is to understand the transition from paper charts to electronic charts, and examine if the control methods of the position sensor used by navigators of today are sufficient with the demands that evolved in the shift from paper charts to electronic charts and the use of ECDIS. This implies if position control methods used on paper charts can be used on ECDIS, and expedient use of new technological aids available on the bridge in an Integrated Navigation System.

1. Identify control methods made for the use of ECDIS on an HSC (literature and field study).

2. Examine teams onboard HSC, and the control methods of position sensor input to the ECDIS in use (field study).

3. Evaluate critically different teams in a controlled environment (simulator) to see how position sensor input to ECDIS is controlled.

4. Explore the system knowledge and “best-practice” of navigators on board HSC (interviews and questionnaire).

5. Formulate recommendations on methods of control of position sensor inputs to the ECDIS on an HSC.

1.4 Value of the Research

With the paradigm shift from paper charts to electronic charts and the use of ECDIS, it has been stated that there is a gap that has evolved when it comes to knowledge of the systems and how to control the position sensor input to ECDIS (Kjerstad, 2003, Norris, 2010). Scholars inquire more research and concrete material from research which they can refer to in their education of new navigators and ECDIS operators. The research done in this thesis will contribute to fill parts of this gap, and will examine if system knowledge regarding ECDIS amongst navigators is at a sufficient level. Parts of this project is meant to be a guidance for navigators onboard HSC in littoral waters on what methods there are to control the position sensor input to the ECDIS, and what are their advantages and limitations. This will include both visual and conventional methods of control. It will also be used in a future revision of “Electronic charts:

Guidelines and recommendations for the Norwegian Navy” (NNC, 2007). The conclusions of the thesis will be distributed to all participants (civilian and military)

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15 who have taken part in the research, which can be implemented into their manuals and procedures.

1.5 Outline Structure

Chapter 1 Introduction: A brief introduction is given on the subject. This is divided into background, research focus, research aim and objectives and value of the research.

Chapter 2 Literature review: Covers regulations and legislation with regards to ECDIS, and definitions are laid down. ECDIS, position sensor input such as GNSS and its augmentation systems are explained briefly. Control methods of ECDIS are discussed and visual and conventional methods of control are explained, with the importance of a well thought out human machine interface to conduct the described control

methods and decrease workload and performance stressing factors for the navigator.

Chapter 3 Research methods: Briefly states the limitations of the thesis. The research will be divided into two main parts: Literature review given in chapter 2 and a field study. The field study is divided into three subsections: Field work on board military and civilian HSC, simulator tests and interviews and questionnaire. The chapter ends with an analysis of the validity and reliability of the field study.

Chapter 4 Findings: Consists of a description and analysis of the observations done on board civilian and military HSC, in the simulator test and from the interview and questionnaire. This is summed up in a synthesis of findings at the end of this chapter.

Chapter 5 Conclusion: The conclusion from the thesis is given in chapter 5, with a subsection of conclusions to each research objective from Chapter 1. It comprises recommendations for future work, and a short summary of conclusions.

All chapters start with a short summary of the thesis so far and an introduction to the chapter, and end with a short summary of the work done in the relevant chapter.

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2.0 Literature review

The field of control of position sensor input to ECDIS in Littoral HSC is a narrow domain, and there is not much literature on this specific matter. However, there is much literature on pieces of my research aim, and the goal of my literature review has been to explore broadly on the matter of position sensor control with ECDIS and its use in HSC. Visual control has been the backbone of a navigator’s art for years, and most methods used on paper charts can be adapted to ECDIS. ECDIS is a large technological leap in navigation, and it is important that all aspects of control of ECDIS are

highlighted. If an engineer asks a navigator what he expects of the future, he will make small adjustments to the equipment which he knows and uses in his day to day work (Norris, 2013a). It can be difficult for a navigator on board a high speed ship using an ECDIS to see what means to use for control, and that is why the literature review is essential to highlight all these means and pitfalls in the use of ECDIS. Starting off with regulations, and continuing along the path of ECDIS, navigational accidents and statistics with regards to the implementation of ECDIS, position sensor inputs,

integrity, control of ECDIS, Human Machine Interface (HMI) and performance shaping factors (PSF) to investigate and distinguish the advantages and limitations in the use of ECDIS.

The International Maritime Organization (IMO) regulates the use of ECDIS, and a distinction between regulations and literature has been made.

2.1 Regulations

IMO is the United Nations organization that handles all matters regarding navigation and maritime transport. In 1974 The Convention of Safety of Life at Sea (SOLAS) was issued and adopted by the member states of the United Nations (IMO, 1974).

Especially chapter V of SOLAS, Safety of Navigation, specifies the requirements for the navigational equipment to be used on board ships entitled to fly the flag of a party to the SOLAS Convention. IMO Member States are obliged to adopt IMO rules and

regulations, such as those in SOLAS, into their national legislation. However, only when the requirements of the Convention have been incorporated into national legislation they affect the individual ships registered by that State.

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17 In 2009 the amendment for Regulation 19 for ECDIS in SOLAS chapter V was put into force, stating that all larger vessels should have and use ECDIS within 2018. This is shown in figure 2.1 below (Scholey, 2010).

Figure 2.1 ECDIS implementation

When it comes to HSC, Paragraph 13.8.2 of High-speed craft (HSC) Code, 2000, details the SOLAS carriage requirements for HSC, which shall be fitted with an ECDIS as follows:

- craft constructed on or after 1 July 2008;

- craft constructed before 1 July 2008, not later than 1 July 2010.

The above implies that all HSC are fitted with an ECDIS.

In Norway it is mandatory with an HSC course, with reference to NOU 1994:9. The course is divided into two main parts. Part one consisting of Crew Resource

Management (CRM), and part two consisting of a technical/operational course (MFA, 1994).

When it comes to training requirements, IMO Model Course 1.27 “Operational use of ECDIS”(IMO, 2012) is adopted to address the training of navigators in the use of ECDIS.

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18 It is divided into 5 areas with 37 topics totalling 40.0 hours. IMO Model Course 1.27 has two fundamental definitions in it; Generic ECDIS Training and familiarisation.

Generic ECDIS Training: ECDIS training to ensure that navigators can use and understand ECDIS in the context of navigation and can demonstrate all competencies contained in and implied by STCW 2010. Such training should ensure that the navigator learns to use ECDIS and can apply it in all aspects of navigation, including the knowledge, understanding and proficiency to transfer that skill to the particular ECDIS system(s) actually encountered on board, prior to taking over navigational duties. This level of training should deliver the competencies at least equivalent to those given in Model Course 1.27 (IMO, 2012).

Familiarisation: Following the successful demonstration of competencies contained in the Generic ECDIS Training, familiarisation is the process required to become familiar with any onboard ECDIS (including backup) in order to assure and demonstrate competency onboard any specific ship’s ECDIS installation, prior to taking charge of a navigational watch (IMO, 2012).

The thesis will also address the use of RADAR when controlling the ECDIS. The RADAR carriage requirements are defined by IMO in the SOLAS Convention Chapter V

Regulation 19 (IMO, 2002). It states that all ships of 300 gross ton (GT) and upwards and passenger ships of any size will be fitted with a 9 GHz radar, or other means, to determine and display the range and bearing of radar transponders and of other surface craft, obstructions, buoys, shorelines and navigational marks to assist in navigation and collision avoidance (IMO, 2002). There are also rules for vessels above 3000 GT, but this is outside the limitations of this thesis.

2.1.1 Definitions

IMO defines ECDIS in the Performance standards for ECDIS (IMO, 2012):

Electronic chart display and information system (ECDIS) means a navigation information system which, with adequate back-up arrangements, can be accepted as complying with the up-to-date chart required by regulation V/20 of

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19 the 1974 SOLAS Convention, by displaying selected information from a system electronic navigational chart (SENC) with positional information from

navigation sensors to assist the mariner in route planning and route monitoring, and by displaying additional navigation-related information if required.

HSC refers to a class of vessels that are characterised by the combination of light ship constructions and the ability to maintaining manoeuvre abilities while holding high speed. The formal definition states that a high-speed craft is a craft capable of maximum speed, measured in meters per second (m/s), equal to or exceeding 3.7∇

0.1667. Where ∇ = Volume of displacement corresponding to the design waterline (m³)³ (IMO, 2008). Design waterline is defined as the waterline corresponding to the

maximum operational weight of the craft with no lift or propulsion machinery active.

Further is a passenger craft defined as a craft carrying more than 12 passengers (Kjerstad, 2003). All the vessels used in this thesis, both in the literature review and in the field study, fulfil the requirements of Kjerstad`s definition.

Navigation in littoral waters (Mann, 2000) is defined as navigation in the inlets, along the coastline, inside the coastline and within sight of land. Distinguishing marks are skerries, underwater rocks and it is a very difficult environment due to the close proximity of land. There is no single definition of littoral waters. One example of this is the vast Norwegian coastline.

Efficient navigation is defined as (NNC, 2012):

The vessel is operating in an optimal way compared to the mission it is executing.

o In the waters the vessel is designed for (keeping good speed).

o With the speed necessary for reaching the aim.

o Constant assessment of the vessel`s opportunities and limitations.

This is a military definition, but can also adhere to an HSC in passenger traffic which aim is to maintain its schedule and conduct a safe passage.

3 The speed represented by the formula but expressed in knots is 7.192 ∇^0.1667

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20 When it comes to integrity monitoring of ECDIS, both Weintrit (2009) and Norris (2010) write how this could be done by different types of integrity monitoring aids. This could be divided into two sections in general, and the author has made a definition which is used throughout the thesis:

Visual control is defined by the author as making observation with the aid of visual sights, such as the traditional cross fix with several lines of position. These

observations can be transferred to the ECDIS through different types of interface.

Conventional control is defined by the author as comparing two (or more) systems or sensors to conduct an integrity check to validate the position on the ECDIS by different types of interface. This can be done by e.g. AIS and RADAR. An example of this is radar overlay (correlation of radar return on conspicuous objects with charted position).

These observations can be transferred to the ECDIS, and is commonly integrated in the INS. Both visual control and conventional control will be further discussed and

explained in the literature review.

Paradigm shift if defined by the author as the transition between paper charts and electronic charts used in an ECDIS, and will be used and referred to throughout the thesis. The author substantiates this paradigm shift with IMO`s Manila Conference in 2010. IMO defines the navigation at operation level of this paradigm shift in STCW, 2010, Table AII/1: “Maintain the safety of navigation through the use of ECDIS” (IMO, 2010, page 32). It is shown with this table that IMO underlines the importance of electronic systems of position fixing and navigation.

2.2 Literature

In the following part of the literature review, there will be an introduction to the ECDIS, and how it presents a paradigm shift for navigators. It is presented with national and worldwide statistics how ECDIS may have had influence on navigation accidents.

Further ECDIS and its position sensor inputs such as GNSS, augmentation systems and DGPS are explained. When it comes to integrity checks and control of position sensor input, visual and conventional control methods are laid down and the importance of integrity checks underlined. RADAR and AIS are two important aids in conventional control and their functioning is described briefly. It is also crucial that the navigators

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21 are familiar with the specific ECDIS system they use, and at the end human machine interface in the use of ECDIS is presented.

2.2.1 Introduction of ECDIS

With the introduction of GPS in maritime use in the 1990s with the interface to ECDIS around 1995 (Kreutzer, 2010), a new era of navigation started. The appearance of computers on the bridge of a ship revolutionised the way of navigation, and is a very good aid if used correctly (Norris, 2010). With the introduction of a new technological aid such as the ECDIS, it might be tempting to say that this aid has made the seaways of today safer, but both national and worldwide statistics indicate the opposite (Figure 2.2, 2.3 and 2.4). The national statistics show that ship accidents decreased from 2000 until 2004, but have increased again after 2004 and are at approximately the same level today as in the year 2000 in Norway (Directorate, 2011).

Figure 2.2 Ship accidents 2000-2010

Grounding means any contact between the vessel and the seabed. No distinction is made between grounding or ground contact. Grounding is recorded as an accident even when damage to the vessel is very limited (Directorate, 2011). The data from the Norwegian Maritime Directorate (2011) does not include a report which states each individual grounding and its causes. The statistics needs further break down to

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22 category of ship, to see the effect on grounding statistics for example with HSC after the time of mounting and starting to use the ECDIS. These statistics have not been found, and this can thus only be seen as a trend and needs further investigation. Note that all larger vessels are to implement and use ECDIS by 2018, so the statistics from 2018 would be of interest to analyse.

The reason for the increase in groundings since 2004 is not clear, but given that the utilization of each ship is equal and the percentage in reports of accidents is

unchanged, there is reason to believe that the increased number of accidents indicates an increased risk of an accident happening (Directorate, 2011). The causal explanations were originally based on simple theories where the relationship between the actual damage caused by the accident and triggering factors was direct and easily

identifiable. It was usually believed that the cause was human or technical failure, and the person directly involved, for example, the master of the ship, was assigned the criminal responsibility (Directorate, 2011).

In recent years other explanatory models have been developed that emphasize an understanding of systems, taking into account various factors that affect the actor in the technical or organizational system of which he or she is a part (Røed-Larsen, 2004).

One decisive system in this organization is the ECDIS and its use in an Integrated Bridge System⁴ (IBS).

Looking into the worldwide statistics from Information Handling Service (IHS) Fairplay (IHS, 2013), we see a slightly different trend. Looking at Figure 2.3, the total amount of serious accidents has risen since 1995, and looking at Figure 2.4, the percentage of distribution of navigational versus non-navigational accidents is slightly increased in the same period. This could imply that the navigation related accidents have risen in frequency since 1995 and the start of the ECDIS era. It does not say anything of this being the ECDIS` fault, but it shows that with the introduction of ECDIS the amount of navigational accidents did not drop significantly.

4 An integrated bridge system (IBS) is defined as a combination of systems which are interconnected in order to allow centralized access to sensor information or command/control from workstations, with the aim of increasing safe and efficient ship's management by suitably qualified personnel.

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23 Figure 2.3 Serious accidents statistics

In this period of time (1995-2012) the ECDIS has been implemented, and the increase in serious accidents might suggest that it could have something to do with the use of ECDIS. From figure 2.4 there is also an increase in the distribution between

navigational and non-navigational accidents, which indicates that something is causing a relative increase in navigation accidents. This is outside the scope of this thesis, and needs further investigation to analyse the statistics and conduct further research in this matter. The statistics used in this thesis is thus to show a trend, and make the reader aware of that even though ECDIS is known to be a good navigation aid for the navigator (Weintrit, 2009), it must be used the correct way to enhance safe navigation (Norris, 2010).

0,0E+00 1,0E-02 2,0E-02 3,0E-02 4,0E-02 5,0E-02

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

Frequency per ship year

Serious accidents

Selected vessel categories (1990-2012)

General Cargo Oil Bulk Dry

Chemical Container Offshore Supply

Ro-Ro Cargo

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24 Figure 2.4 Distribution of navigational versus non -navigational accidents Antão and Soares (2007) conducted a study on HSC accidents compared to

conventional ocean-going vessels. From the analysis one could see that the HSC accidents and incidents are mainly related to bridge personnel and bridge operations, where the human element is the key responsible factor in the majority of the

accidents. When compared with ocean-going vessels, it is clear that navigational equipment and procedures have a larger preponderance in the occurrence of

accidents of HSC. This comparison is shown in Figure 2.5, and make especially note of the first bar which shows navigation incidents (Pedro Antão, 2007).

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25 Figure 2.5 Comparison of factors in serious incidents HSC and Commercial vessels.

2.2.2 ECDIS

The ECDIS system can be used to meet IMO/SOLAS chart carriage requirements provided it meets the specified IMO performance standards. The ECDIS must be ‘type approved’ to ensure it meets these performance standards. An ECDIS that does not comply or follow the relevant performance standards is classed as an Electronic Chart System (ECS)⁵ (IMO, 1995).

Some ECDIS systems offer additional databases for tidal information, including predictions and automatic calculation of high water, low water, tidal heights and streams. However, care should be taken when using such information as not all data provided by ECDIS manufacturers is officially authorised or approved by flag states (Standard, 2011).

5ECS is not certified as a ‘type approved’ ECDIS and does not meet or comply with IMO/SOLAS performance standards. The ECS may allow the use of electronic navigational charts (ENC) and raster navigational charts (RNC) with comparable functionality to a ‘type approved’ ECDIS, but should not be solely relied upon for navigation as the system is not tested nor certified.

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26 Masters and officers should be aware of the limitations of ENC data, including the dangers of overreliance on ECDIS. ENC data can cause operator error particularly as electronic navigational charts contain digitally layered information. Overreliance on ECDIS when using ENC data may prove dangerous if inadequate training and

familiarisation has been given (Norris, 2010).

The ECDIS is a complex system that is an aid and navigation tool for the navigator for safe navigation (Kjerstad, 1997b). Its main features are the Electronic Navigation Charts (ENC) and a selection of the inputs given to the ECDIS is amongst others GPS, gyro, echo sounder, speed log, RADAR and AIS. This can vary from ship to ship, but a position sensor input of some kind is needed, and most common is the GPS. ECDIS shows up-to-date information on one screen, has integrated additional services (e.g.

AIS, RADAR), enables passage planning and passage monitoring, and enables quick response to emergencies (Norris, 2013a). The complexity of one ECDIS system is shown by the ECDIS system from the manufacture FURUNO in the figure below (FURUNO, 2011).

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27 Figure 2.6 ECDIS interface

As seen from the figure, there are several inputs to the ECDIS, and this is just one of many systems. When on board a military ship the systems get more complex and the sensor inputs increase, and an example of a military IBS is shown in Figure 2.7 (Kongsberg, 2008). This implies that the user of the system, the navigator, has extensive system knowledge of the system if something fails.

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28 Figure 2.7 IBS of a military ship

When using the ECDIS it is important for the user to know which type of electronic charts and which data quality they contain (Horst Hecht, 2011). The Category of Zone of Confidence in Data (CATZOC) is an essential object attribute to ECDIS, and indicates that the ENC data meets minimum criteria for position and depth accuracy (Norris, 2010). There are six category levels, defined in Table 2.1 (detailed notes omitted) (IHO, 2009).

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29 Table 2.1 Category of Zones of Confidence Definitions

With the increased use of technology and integration in different IBS, the demand for system knowledge of the navigator is rising. It has been suggested that the new

generation of navigators with higher computer competence than previous generations, will have an advantage when it comes to the use of ECDIS (Smit, 2012). This topic has been studied by Smit (2012) and the finding indicates that those with experience in similar systems had both higher initial and end scores thus indicating relative less

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30 perceived learning outcomes. The link between navigational competence and

computer competence is shown in Figure 2.8 (Smit, 2012, p. 3)

Figure 2.8 Domains of ECDIS competence

Figure 2.8 shows that computer competence as rooted in a more general domain did not transfer to the other, more specific domains, even though some of the

competencies were apparently similar. The assumption in the industry itself that the young deck officers have grown up with computers and should be better on ECDIS because of their presumed computer literacy (Norris, 2010), is not supported in this finding. Durso et al. (2006) found that the relationship between experience and performance was not straightforward and there was no evidence for claiming that the quality or even the length of experience necessarily would influence performance positively. Especially when experience in a domain was challenged by a more unusual task, the experienced would not always use his expertise in a profitable way. Similarly when the participants in the ECDIS course used the new tool, they apparently did not make use of former experience in traditional navigation to enhance learning in the use of ECDIS.

With new technology, the problems with technology-assisted accidents occur (Timmons, 2009, Kjerstad, 2008). ECDIS-assisted groundings have become a new challenge that navigators have to be aware of (MAIB, 2008, TNI, 2013). The mandated

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31 use of ECDIS springs from the promotion of safety of life at sea. It is a fundamental, though sometimes misunderstood, safety tool that demands real commitment to play its role correctly (IMO, 1995). Skimp on that commitment, fail to provide training and monitoring and the results can be ECDIS-assisted groundings and collisions and a lingering suspicion that ECDIS is another technology foisted on already over-worked navigators and superintendents (UKHO, 2011). When reading the accident reports of ECDIS-assisted groundings (TNI, 2010), a subject immediately becomes clear: where officers are inadequately trained and the equipment is incorrectly set up then things go wrong. In fact, there are comparatively few instances of ECDIS-assisted groundings, but those there are tend to seized on by those who think that every technological step forward is actually a step back. This underlines the importance of system knowledge and familiarisation with the relevant ECDIS system on board (Norris, 2010).

2.2.2 Position sensor inputs

2.2.2.1 GNSS

GNSS has by many been seen as the holy grail for navigation, giving the absolute position at any given time (Spaans, 2000). The most common GNSS solutions of today are GPS, GLONASS, GALILEO and COMPASS/BEIDOU (Hofmann-Wellenhof, 2008). All the different GNSS solutions provide the user with instant position solution of a given accuracy. It is of high importance that the navigator knows the possibilities and limitations in the GNSS which is interconnected to the ECDIS, providing the navigator with an up to date position of the vessel (Spaans, 2000).

Official U.S Government information about the GPS announced that GPS Standard Positioning Service (SPS) Performance Standard will provide a "worst case"

pseudorange accuracy of 7.8 meters at a 95% confidence level (MoD, 2008). The accuracy of the GPS signal in space is actually the same for both the civilian GPS service (SPS) and the military GPS Precise Positioning Service (PPS). However, SPS broadcasts on only one frequency, while PPS uses two. This means military users can perform ionospheric correction, a technique that reduces radio degradation caused by the Earth's atmosphere. With less degradation, PPS provides better accuracy than the basic SPS (MoD, 2007).

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32 The precision of the GNSS solution is given by a Dilution of Precision (DOP) value to specify the additional multiplicative effect of navigation satellite geometry on positional measurement precision. To get the position accuracy of a given system, multiply the given accuracy with the DOP value (accuracy of 30 meters with 1,5 DOP value equals 45 metres) (Langley, 1999). There are several different DOP values (HDOP⁶, VDOP⁷, PDOP⁸, GDOP⁹ and TDOP¹⁰) and for mariners who are always at sea level the Horizontal DOP value is crucial. High and low DOP values with regards to satellite constellation are given in Figure 2.9 (Langley, 1999).

Figure 2.9 Dilution of Precision Formula used (Langley, 1999):

The actual accuracy users attain depends on factors outside the system operators control (US MoD), including atmospheric effects and receiver quality (shown in Table 2.2).

There are several error and bias sources in the accuracy of a GNSS solution. The biggest contributor is the ionosphere, but error in satellite coordinates and clock and bias from the troposphere and receiver noise also contribute to the total amount of

6 Horizontal DOP

7 Vertical DOP

8 Positional DOP

9 Geometric DOP

10 Time DOP

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33 error. This is shown in Table 2.1 (Bingley, 2012b). Error is shown in plan and height, and is given in meters.

Error Full mitigation

plan/height

Simple mitigation plan/height

Sat cords (e) 1/2,5 1/2,5

Sat clock offset (e) 1,5/4 1,5/4

Ionosphere (b) 0/0 10/25

Troposphere (b) 0/0 2/5

Receiver noise (b) 0,1/0,25 0,1/0,25

TOTAL 3/7 15/37

Table 2.2 GPS error and biases

Simple mitigation means that the ionosphere and troposphere models are simple and not sufficient to mitigate the bias. Expensive receivers use full mitigation (most marine GPS receivers), while cheap receivers (iPhone) use simple mitigation (Bingley, 2012b).

There is also influence from other sources that the user of a GNSS system needs to be aware of. Multipath is when a satellite signal arrives at the receiver antenna by more than one path, shown in Figure 2.10 (Bingley, 2013). This is caused by reflecting

surfaces near the receiver antenna. This is important to be aware of when operating in an area where multipath can occur, such as the Norwegian fjords.

Figure 2.10 Multipath

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34 2.2.2.2 Augmentation systems

For a number of applications, GNSS as sole-means or augmented, has some deviances and its performance does not satisfy the user`s requirements. Space Based

Augmentation Systems (SBAS) such as The European Geostationary Navigation Overlay Service (EGNOS) or The Wide Area Augmentation System (WAAS) consist of a space, ground and user segment (Elliott D. Kaplan, 2006, Kjerstad, 1997b). The receiver stations in WAAS and EGNOS form a Wide area Ground-based Network which gives Wide Area DGPS Corrections and Independent Integrity Monitoring (IM). The

communication satellites in WAAS and EGNOS provide Broadcast DGPS and IM data to the users and provide additional Ranging source (only with WAAS), via a GPS-like signal within the coverage area. This provides for the users (Norris, 2013a):

1. Improved accuracy

a. Corrections sent to the user 2. Improved integrity

a. Independent Integrity Data b. Additional ranging

3. Improved availability and continuity a. Added ranging source

b. As a consequence of improved ranging

Figure 2.11 shows the benefits of an SBAS system compared to Ground Based Augmentation Systems (GBAS), such as Ordinary Differential GPS (ODGPS) (V.

Ashkenazi, 1993). As shown the error stays the same in SBAS systems when the baseline increases, but be aware that it is within the SBAS coverage area. SBAS is also known as Wide Area Differential GPS (WADGPS). The figure points out the importance of being close to a reference station if using GBAS, and shows the advantages with the SBAS when it comes to accuracy as long as you are within the SBAS coverage area. Plan error is significant for mariners, because the vessel is always at sea level.

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35 Figure 2.11 Comparison WADGPS and DGPS

The use of GNSS systems in the high-north is vulnerable even when using

augmentation systems such as EGNOS or WAAS (Kjerstad, 2006a). Also with global warming and new navigation routes opening, such as the Northwest and Northeast passage, the challenges for GNSS systems are increasing (Kjerstad, 2011).

2.2.2.3 DGPS

Ground Based Augmentation Systems such as DGPS is common in the marine world.

The underlying premise of DGPS is that any two receivers that are relatively close together will experience similar atmospheric errors. DGPS requires that a GPS receiver be set up on a precisely known location. This GPS receiver is the base or reference station. The base station receiver calculates its position based on satellite signals and compares this location to the known location. The difference is applied to the GPS data recorded by the second GPS receiver, which is known as the roving receiver. The corrected information can be applied to data from the roving receiver in real time in the field using radio signals (Bingley, 2012a, Kjerstad, 1997b). In the marine world the DGPS is a great resource, and many vessels have the opportunity for such a position input (Moore et al., 2002). The errors and biases to the DGPS are shown in Table 2.2

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36 (Bingley, 2012a), distance in nautical miles (NM) from rover station to user receiver.

Error is shown in plan and height, and is given in meters.

Error 10 NM plan/height 270 NM plan/height

520 NM plan/height

Sat coords (e) 0/0 0,05/0,125 0,1/0,25

Sat clock offset (e) 0/0 0/0 0/0

Ionosphere (b) 0/0 1/2,5 2/5

Troposphere (b) 0/0 0,2/0,5 0,4/1

Receiver noise (b) 0,1/0,25 0,1/0,25 0,1/0,25

TOTAL 0,1/0,25 1,35/3,4 2,6/6,5

Table 2.2 DGPS bias and errors

It is important to note that these figures are given to illustrate the amount of errors and biases from each source, and are not to be considered as upper limits (Bingley, 2012a).

2.2.2.3 LORAN

Long Range Navigation (LORAN) is a terrestrial radio navigation system which

determines position and speed from low frequency (100 KHz) radio signals transmitted by fixed land based radio beacons. There have been several versions of LORAN, and the latest being LORAN-C and enhanced LORAN (eLORAN) (Kjerstad, 1997b). eLORAN is a LORAN system that incorporates the latest receiver, antenna, and transmission system technology to enable LORAN to serve as a backup and complement to GNSS for navigation and timing. This new technology provides substantially enhanced

performance beyond what was possible with LORAN-C, eLORAN`s predecessor. For example, it is now possible to obtain absolute accuracies of 8-20 meters using eLORAN for harbour entrance and approach (ILA, 2010).

The importance of having a back-up system to GNSS is actualize by GPS jamming attacks from North Korea towards South-Korea that have increased in frequency and duration since they began in August 2010. The jamming have prompted the South Korean government to implement an eLORAN system that will cover the entire country by 2016 (GNSS, 2013).

2.2.3 Integrity

The ECDIS will provide an alert if it detects a problem with connected navigational equipment. A concern is that many problems with position will not be automatically

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37 detected, especially when using a simple GPS-only positioning system (Norris, 2010).

The need for integrity of position on ECDIS can be compared with the need for

continuous position control in the paper chart before the introduction of ECDIS. Use of ECDIS simplifies integrity assessment, but the immediacy of own position shown on a computer can give a false sense that integrity checking is unimportant (Norris, 2010).

It is fundamental to make integrity checks on the ECDIS to whatever position sensor input the navigator chooses to use on board the vessel. Over-reliance in ECDIS as a navigation tool without proper integrity monitoring can cause navigational errors.

Navigators of today rely too much on what is displayed on the screen, and use the ECDIS in “PlayStation” mode (Norris, 2013a, Kreutzer, 2010, Norris, 2010). Integrity is defined by:

Ability of the system to provide the user with data within the specified accuracy in a timely, complete and unambiguous manner. If integrity is compromised, the system should alert the user that all or certain data should be used with caution or not at all (Norris, 2013a).

Integrity incorporates the following concepts (Norris, 2013a):

1. Validity: The conformity of information with formal or logical criteria, or the marking of data as being good or not. E.g. the GPS has too few satellites to give a position solution, and then the data should be marked as invalid.

2. Plausibility: Received or derived data should be checked for plausibility. E.g.

data from the log speed sensor are showing that the vessel is moving at twice the maximum speed, or if the visual sights give the navigator a different position (visual control). Data are invalid.

3. Latency: The time interval between an event and its result. Data should only be combined if the differential latencies are compatible with giving a meaningful result. E.g. the use of data from other ships from the RADAR compared with AIS.

4. Comparison: The integrity of information should be compared between (at least) two different sensors. E.g. GPS, Loran-C and visual sights.

Examples of integrity tests can be (Norris, 2013a):

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38 1. GNSS Receiver Autonomous Integrity Monitoring (RAIM) (Hofmann-Wellenhof,

2008).

a. RAIM detects faults with redundant GPS pseudorange¹¹ measurements.

When more satellites are available than needed to produce a position fix, the extra pseudoranges should all be consistent with the computed position. A pseudorange that differs significantly from the expected value (an outlier) may indicate a fault of the associated satellite or another signal integrity problem (e.g. ionospheric dispersion).

Traditional RAIM uses fault detection (FD), however newer GPS

receivers incorporate fault detection and exclusion (FDE) which enable them to continue to operate in the presence of a GPS failure.

2. Comparison of positioning sensors.

a. This is a comparison between primary and secondary positioning sensors, and it will give an alert when the set limit has been exceeded.

b. Position Deviation Alarms. Comparison of primary and secondary position sensor input, and an alarm will sound if a limit value is exceeded. This value can be adjusted in the setup of the ECDIS.

3. Correlation of ECDIS with RADAR and/or AIS.

a. Radar overlay on ECDIS or chart contour overlay on RADAR from ECDIS.

b. Use of parallel indexes on the RADAR set.

4. Measured depth (from echo sounder) with chartered depth (used by submarines).

5. Correlation of radar overlay with conspicuous targets.

6. Integrity check by visual sights (e.g. 3 lines of position and other means of visual sights).

2.2.4 Control of ECDIS

Control of the position sensor input to the ECDIS can be done by several methods, but the use of visual sights and the use of conventional methods such as radar for

positioning are the most common. The use of visual sights such as cross bearing, 4- bearing, ½-bearing and aft heading point is discussed in a previous master thesis

11 The pseudorange is a measure of the range, or distance between the GPS receiver and the GPS satellite. Since there is accuracy errors in the time measured, the term pseudorange are used rather than ranges for such distance.

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39 written at the University of Nottingham (Bøhn, 2011), and a short description of these methods is given in Appendix G. There is also literature used at the Royal Norwegian Naval Academy that lay these principles out (Oi, 1993, Kjerstad, 1997a), and it can also be found in English publications (National Research Council, 1994). It is important for the reader to understand that these matters of visual sights are something that every military navigator has in his backbones, and it is applied both on paper and digital charts. Civilian navigators do not use visual control methods to the same extent, but it is covered in the syllabus of a navigation degree (UiT, 2013). On ECDIS, you have the opportunity of taking several position lines (Norris, 2010), similar to cross bearings. All other methods of position fixes are also possible on the ECDIS, but the layout and interface are different from manufacturer to manufacturer.

With more and more technology being added to the working environment for the navigator, there are several conventional methods of control with technological aids which can help the mariner in controlling the ECDIS. Interface with RADAR and AIS are two essential aids. With the use of overlay from RADAR, or even overlay from ECDIS to the RADAR, the mariner can compare the position sensor input (e.g. GNSS) with the picture from the RADAR (Norris, 2008). This is shown in the figure below where chart contour is used on the RADAR.

Figure 2.12 Chart contour overlay on RADAR

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40 2.2.5 RADAR

It is essential to be aware of the possibilities and limitations in the RADAR set when using it to control the ECDIS (Norris, 2013b). There are several manufacturers within the RADAR industry, and the parameters are different from set to set. It is decisive to use a conspicuous target, and be aware of which directions the RADAR has the best functionality. Land and targets in front of the vessel will be strained and will seem bigger than they are. Land and targets abeam and closer to the vessel will be

presented more exact (Skolnik, 2001). It is important that the navigators assess each target or land details that are used for the control of RADAR, and that the navigator is aware of the possibilities and limitations of his/her RADAR set. HSC have a RADAR set operating in the 9 GHz band (X-band) (IMO, 2002). RADAR theory is outside the scope of this thesis, but a recommended book is Introduction to Radar Systems by M. I.

Skolnik (2001) or Basic Radar Theory written by KNM Tordenskjold (2002).

Fundamental parameters for the navigator to be aware of are: Frequency, horizontal beam width, pulse repetition frequency (PRF), rotation per minutes (RPM), pulse length (short, medium and long) and it is essential that the navigator knows how to tune the given RADAR set to the given weather conditions (tune, gain, anti-clutter sea, anti-clutter rain). Note that a RADAR set needs constant tuning with changing weather conditions, and is not supposed to be set on a “standard” setting.

2.2.6 AIS

Automatic Identification System is a maritime navigation safety communications system standardized by the International Telecommunication Union (ITU) and adopted by the International Maritime Organization (IMO) that provides vessel information, including the vessel's identity, type, position, course, speed, navigational status and other safety-related information automatically to appropriately equipped shore stations, and other ships within VHF-range. It is a VHF based system on two channels, typically 87B and 88B (162 MHz). In short terms AIS is an automatic radio

communication system where all ships broadcast information about themselves on two different VHF frequencies (IMO, 2001, IMO, 1998).

The data transmitted is divided into three subgroups (Norris, 2008, IMO, 1998):

1. Static data

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41 a. IMO number, Ships name, Call sign, Type of Vessel and location of

position-fixing antenna on the ship.

2. Voyage related data

a. Destination, Estimated Time of Arrival (ETA), ships draught, cargo and route plan (optional) is transmitted every 6th minute.

3. Dynamic data.

a. Position, time in UTC¹², heading, course, speed, navigational status, rate of turn, pitch and roll (optional) and angle of heel (optional) is

transmitted every 2 seconds to 3 minutes dependent on the vessels current speed. That means that a high speed vessel transmits its data every other second and a ship at anchor transmits its data every 3rd minute.

Control of the position sensor input to ECDIS can also be controlled by comparing the echoes from a vessel on the radar with the AIS track, which gives a good indication on deviation in the position sensor input (either on the ECDIS or the AIS). This is shown in Figure 2.13 and Figure 4.9 (page 74).

12 Coordinated Universal Time (UTC; French: Temps Universel Coordonné) is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to

Greenwich Mean Time (GMT). For most purposes, UTC is synonymous with GMT, but GMT is no longer precisely defined by the scientific community.

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42 Figure 2.13 Comparison of RADAR track and AIS track.

When controlling the ECDIS, AIS can be used as an indication whether or not the GPS is working properly. If there is a deviation between the RADAR track and the AIS track, this is an indication of deviation on the system and should be looked into. It might also be a technical error in the AIS, and AIS is also easy to spoof. Most AIS have a built-in GPS, and an error in the built-in GPS in the AIS can arise. This error in the built-in GPS in the AIS can accrue independent of an error in the primary GPS sensor of the vessel (Norris, 2008).

When using the AIS integration on the ECDIS and the RADAR, it is crucial to be aware of the AIS fusion function (Norris, 2008). This fusion is to be used to provide the navigator with less information, and therefore the track from the RADAR and the AIS is fused into one track which is presented. If there is a deviation in the system, the fusion function can prevent the OOW of seeing this as the two targets from the RADAR and the AIS are fused within a given distance limit. This limit can be adjusted on the different sets, and it is important that the OOW knows which limits are used if the AIS is to be used to detect deviation in the position sensor. The OOW should assess if the

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43 fusion functions should be turned off if he/she suspect deviation and want to control the ECDIS by comparing AIS and RADAR track data.

2.2.7 Familiarisation

The introduction of ECDIS also demands new training for navigators. IMO Model Course 1.27 “Operational use of Electronic Chart Display and Information Systems (ECDIS)” is covering this aspect (IMO, 2012), and consist of two main parts: Generic ECDIS training and familiarisation. This course has been revised by IMO several time, and the latest version being from 2012. During the past years, there have been several studies on what this course should comprehend. System knowledge, simulator training in the use of the system and familiarisation of the specific system which is used on board are main findings and topics which are stressed (Kjerstad, 2006b).

There are many different manufacturers of ECDIS solutions, and there are just as many different ways of interface and set-up on the ECDIS which the mariner must know how to use. This is why familiarisation is very important for a navigator on board the ship using the systems which the navigator will use in his/her day-to-day work (Gale, 2009).

One of the problems with many different manufacturers of ECDIS is that the layout and interface is slightly different from one producer to another. This is confusing for a navigator when changing vessels, and he/she has to cope with a new system with slightly different interface on its ECDIS. Familiarisation of the equipment which the navigator is to use is therefore fundamental (Norris, 2010). Users that are new to an ECDIS-installed ship must confirm they have sufficient knowledge of the system on board. Such check lists can be found in Norris (2010) page 193-198 and is a good guidance for the navigator when it comes to the familiarisation of the vessel specific ECDIS. Compared to aviation, which only has two major manufacturers (Boeing and Airbus), the use of check-list and the importance of familiarisation have been neglected (Bonner, 2013).

2.2.8 Human Machine Interface

Robbins (2007), Gould (2009), Knappen-Roeed (2008) and Dobbins (2004) have looked at Human Machine Interface in general and in HSC in specific. Results from studies have shown that the introduction of ECDIS improves the course-keeping performance, and significantly reduces the total amount of communication on the bridge. It is also

Control of position sensor input to Ecdis on high speed craft